A cokpobation of



sept. 27, 1927. 1,643,669

H. S. LOOMIS RAILWAY BRAKING APPARATUS Filed Deo. 26, 1925 PatentedSept. 27, 1927.

UNITED STATES PATENT OFFICE.

HAROLD S. LOOMIS, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR Tt')` THE UNIONSWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

RAILWAY BRAKING APPARATUS.

Application led December 26, 1925.

My invention relates to railway braking apparatus, and particularlytoapparatus of the type comprisingr trackway mechanism adapted to engagea part of a railway vehicle. l

I will describe one form of railway brakinc apparatus embodyingr mvinvention. and will then point out the novel features thereof in claim.

The accompanying drawing is a view, partlv diagrammatic. illustratine:one form of railway braking' apparatus embodying my invention. l

Referring to the drawing. the reference characters 4 and 4. designatethe two track rails of a stretch of railway track provided with trackwaybrakingr mechanism. In the torno here shown. this mechanism comprisestwo braking bars 5 and 6. located on opposite sides of the rail 4 andarranged to en- .Qaae the two sides disposed in parallel relation of awheel of a. car pas-siner along the track. Two similar brakino hars 5and 6 are located on opposite sides of the track rail 4.

The brakiner bars 5. 6. 5 and 6. are com trolled bv a fluid pressuremotor device desianated bv the reference character As here shown. thismotor device comprises a cylinder 1 containing a reciprocable piston 2.This piston carries a plunger 3. which is operatively connected with thehrakinfr hars through the medium'of link work 7. It will a be plain fromthe drawing. that when the piston 2 is in its left-hand position. thebraking hars are in their non-braking positions. When piston 2 is drivento its righthanrl `position in cvlinder 1. however. the braking barsassociated with each of the track rails are urged toward the rail so asto engage the sides of the wheels of a railway vehicle. bars 5 and 5*moving toward the right, and hars 6 and 6 moving toward the left.

The reference character B designates a. magnet valvecomprising a valvestem 8 provided with an armature 8*l and a windingr 9. When winding 9 isenergized. the left hand end of cylinder 1 is connected with a suitablesource of fluid pressure, not shown in the drawing. through pipe 10,valve B. and pipe 13. When winding 9 is de-energized. however, the valveBis closed, so that the Serial No. 77,751.

supply oit fluid pressure from pipe 10 to cylinder 1 is discontinued. Asecond valve C comprises a valve stem 8 which is also provided with awinding; 9 and an armature 8a. and is so arranged that when winding` 9is cle-energized cylinder 1 on the lett-hand side of piston 2 isconnected with atmosphere throuefh pipe 14. valve (l and port 11. It,however. winding 9 is enereized. valve stem 8 is drawn downwardly toblank pipe 14 and prevent the escape ot' fluid pressure trom cylinder 1.A, third valve` designated hv the reference character D. controls thesupplv of fluid pressure to the richt-hand end ot cvlinder l. lllfhcnthis valve is cle-enen .r1-ized. pine 12 communicating with therichthand end ot cylinder 1 is connected with atmosphere throufrh port11. Wien nndinoq 9 of valve D is cneroizf-id. however valvel stem 8 ismoved downwardlv and pipe 12 is disconnected from port 11 and isconnected with a source oi duid pressure. not shown in the drawinfr.throue'h pipe 10.

The three valves l?. and l). are controlled by a manually operablecircuit controller dcsirrnated hv the reference character K. and bvthree automatic circuit nontrollcrs E. F and (l. Referring narticularlvto circuit controller the reference character 16E desifrnates alpressure responsive unit.. such` for example. as a `Bourdon tube. whichcontrols a contact 17E. so that when thc pressure in the Bourdon tube16E exceeds predetermined amount. the contact 17E will be open. rlhecircuit controllers F and G are constructed in the sance manner as thecircuit controller lll. and ch ot the Bourdon tubes 16E. 161 and 16G isconnected with the letthand end oi cylinder 1 throucfh a pipe 15. Theparts are so proportioned that the circuit controllers F. and G operateat dit* ferent pressures. For purposes ot' explanation. I will assumethat all ot' thc circuit controllers F and G are closed at pressuresbelow 25 lbs. per square inch. At all pressures above 25 lbs. per squareinch. contact 1'?G is open. at all pressures above 50 lbs. per squareinch. contact 1'?F is open. at all pressures above '75 lhs. per squareinch. contact 17E is open.

The circuit controller K comprises a pivoted lever 18 and a pluralityot' fixed contacts 21, 22, 23, 24 and 25 which may be selectivelyengaged by the lever 18, depending upon its position. rl'he circuitcontroller l also comprises a contact segment 20, so disposed that Whenlever 18 engages contact 21 or contact 24, or occupies any positionintermediate these tivo contacts, the lever Will also engage thesegment' 20. Carried on lever 18 a push button designated by thereference character 19. his push button is normally closed, but isarranged to be opened manually.

lts shoWn in the drawing, all ot the valves B, C and D, are dc-energizcdand the piston 2 is in its lett-hand position, so that the 'I brakingbars located in the tracliWav are in their non-brak ng or inetlectivepositions. .l Will iirst assume that the operator Wishes to make a lightbrake application. To accomplish this, he moves lever K into engagementWith contact 24. ln so doing, the lever 18 also engages segment 20. Pushbutton 19 is closed, so that current tloWs trom a suitable source otenergy, such a battery J, through Wire 26, push button 19, Wire 18a,

` lever 18, segment 20, Wire 2i, Winding 9 .ot

valve C, and Wires 28 and .29 back to battery J. Valve C is thereforeclosed to blank pipe 14 and prevent the escape ot' tluid pressure tromthe lett-ha d end ot' cylinder 1. fit the same time. current tloWs trombattery J,

through Wire 26, bush button 19, Wire 18, lever 18, Contact 2st, Wire31, Contact 17C ot circuit controller G, Wires 82, 83. 34, and 85,Winding 9 ot valve B, and Wires 86 and 29 back to battery J. Valve B istherefore opened and fluid pressure is supplied to the lett-hand end otcylinder 1 forcing piston 2 and plunger B carried thereby, to the right,and urging the braking bars into their brake applying positions. lt thetrack rails l and el are occupied by a railWay vehicle, the braking barsand 6 Will engage the flanges ot the Wheels With a torce Which dependsupon the pressure supplied to cylinder 1. T."Vhen this pressure reacheslbs. per square inch, the contact 17G opens, thereby inter'- rupting thecircuit just traced tor Winding 9 ot valve B and interrupting the supplyof pressure to cylinder 1. It the pressure in cylinder 1 is decreased,as by leakage past the piston 2, to a value beloW 25 lbs. per squareinch, contact 17C' immediately closes and restores the pressure to theproper value.

Should the operator Wish to increase the braking torce applied to thebraking bars in the track Way to lbs. per square inch, tor example, hemoves lever 18 into engagement With contact The lever still engagessegment 2O and valve C is therefore still closed. The circuit justtraced ifor Winding 9 ot valve B is noW broken, hoW- ever, but a neWcircuit is closed from battery il, through Wire 26, contact 19, Wire 18,lever 18, contact 28, Wire 2l, con act 17F oi circuit controller F,Wires 88, 33, 8st and 85, Winding 9 of magnet valve B, and Wires 36 and29 back to battery J. The valve B is noW energized over this neW circuitso the fluid pressure is supplied to cylinder 1 until the pressure inthe lett-hand end ot the cylinder reaches 50 lbs. per square inch.Contact 17T then opens. The pressure in the lett-hand end of cylinder 1is thereafter maintained at the proper value, as explained in connectionWith circuit controller G. In similar tashion, it lever 18 is moved intoengagement With contact 22, magnet valve B is energized over contact17E, so that the `pressure in the lett-hand end ot1 cylinder 1 Will thenbe maintained at 75 lbs. per square inch. The circuit tor valve B Willthen be from battery J., through Wire 26, push button 19, Wire 18a,lever 18, Contact 22, Wire 89, contact 17E, Wires s0, 311, and 35,Winding 9 of valve B, and Wires 36 and 29 back to battery J. Finally,When lever 18 is moved into engagement With contact 21, current tloWsfrom battery J, through Wire 26, push button 19, Wire 18, lever 18,contact 21, Wires ll1 and 85, Winding 9 ot' valve B, and Wires 86 and29, back to battery J'. lt Will therefore be plain that When the lever18 is in this position, ,the control ot magnet valve B is independent otthe pressure existing in cylinder 1 and that the full amount ot pressureavailable in pipe 10 Will be admitted to the tluid pressure motor A. togive a maximum braking effect.

I Will noW assume that the lever 18 is in engagement With Contact 21, sothat full braking pressure iseXerted by the braking apparatus, and thatthe opera-toif'Wis'lies to reduce the braking torce to thatcorresponding to a pressure of 25 lbs. per square inch in the lett-handend of the cylinder 1. To accomplish this, the 4operator moves lever Kinto'engagement With contact 24. Valve C is still closed, and valve B isalso closed because Contact 17G is noW open. The operator then openspush button 19. As a result, the circuit is opened for magnet valve C.Which valve immediately opens and vents the lett-hand end of cylinder 1to atmosphere. This operation is continued until the pressure in thelett-hand end of cylinder 1 is someWhatbeloW 25 lbs. per square inch.The push button 19 isv then released, so that the circuit is againclosed tor valve C Which valve immediately closes. The pressure incylinder 1 is noW beloW 25 lbs. per square inch, so that contact 17G isclosed and valve B is energized to raise the pressure in the cylinder to25 lbs. per square inch. The operation of the apparatus foraccomplishing a reduction in braking pressure tro-m any higher pressureto any loWer pressure Will he readily understood from the Jforegoing. ltshould be particularly pointed out in this connection. hoWever., thatWhenever the push button 19 is opened to vent the cylinder to atmospherethrough valve C, the circuit for valve B is also opened, no matter whatthe pressure in the cylindermay be. It follows that only one of valves Band C can be open at any one time so that it is impossible to waste morethan one cylinder full of air at one time.

If the operator wishes to restore the bralr ing bars to theirineffective positions` he first moves lever 18 to the position in whichit is illustrated in the drawing. All contacts are then open, so thatvalve B is closed and valve C is open. The left-hand end of cylinder lis therefore connected with atmosphere. The operator next moves lever 18into en gagement with contact 25. Current then flows from battery J,through wire 26, push button 19, wire 18, lever 18, contact 25, wire 30,winding 9 of valve D and wire 29 back to battery J. Valve stem 8 ofvalve D therefore moves downwardly and fluid pressure is supplied to theright-hand end of c ylinder 1` Piston 2 is therefore driven to the leftand the braking bars are moved to their non-braking positions. With thebraio ing' apparatus thus released, the operator returns lever 18 to theposition shown in the drawing, thereby de-energizing valve D andrestoring' the apparatus to its normal condition.

I do not claim as my invention the combi nation of a plurality ofpressure responsive devices subjected to the pressure in the operatingcylinder and in turn actuating a plu` rality of circuit controllers forgoverning the valve which admits fluid pressure to said cylinder, suchcombination being the invention of John P. Coleman and disclosed andclaimed by him in an application for Letters Patent of the UnitedStates, filed April 26, 1926, Serial No. 104,566, for railway brakingapparatus.

Although I have herein shown and de scribed only one form of railwaybraking apparatus embodying my invention. it is un- "e-:ffod thatvarious changes and modifica tions may be made therein within the scopeof the appended claim without departing from the spirit and scope of myinvention.

Having thus described my invention what I claim is:

Railway braking apparatus comprising a braking bar located in thetrackway, a fiuid pressure motor for actuating the bar, a first windingfor controlling the admission of fluid to the motor, a second windingfor controlling the exhaust of fluid from the motor, a source of energyhaving one terminal conneeted with one terminal of each of saidwindings, two fixed Contact members connected with the free terminals ofsaid two windings respectively, a manually operable lever movable intoengagement with both fixed contacts but not with either fixed contactalone, and manually operable means 'for connecting the free terminal ofthe source with said lever.

In testimony whereof I aflix my signature.

HAROLD S. LOOMIS.

